Bolted connection for plug-in device



Aug. 411, 1964 E. T. PLATZ ETAL 3,144,588

BoLTED CONNECTION FOR PLUG-1N DEVICE Filed Jap. 2o. 19Go FEET- 5. T-I 5 1-- 39 J/ 4a 2f Arve/WW United States Patent O BOLTED CONNECTION FOR PLUG-IN DEVICE Elwood T. Platz, Detroit, and John A. Herrmann, Grosse Pointe Farms, Mich., assignors to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Jan. 20, 1960, Ser. No. 3,525 20 Claims. (Cl. 317-119) This invention relates to molded case circuit breakers in general and more particularly to a combination terminal means therefore which includes provisions for a plug-in connection to a panelboard stab and, in addition thereto, a bolted connection tothe stab.

Spring clips of the type disclosed in U.S. Patent 2,875,289 for connecting the line side of a circuit breaker to the feeder bus of a panelboard are in wide spread use today. However, for certain applications it is desirable to utilize a bolted connection. That is, additional contact area may be desired or for applications in which the panelboard will be subjected to severe mechanical shock additional secureness is desired.

The instant invention provides a bolt type connection while still retaining the convenience of a plug-in spring clip connection. This is accomplished by utilizing a conventional terminal means which includes a spring clip provided with a forwardly extending lug. The lug is provided with a notch in the forward end thereof through which the threaded portion of a clamping screw passes and is thereafter received by a threaded slot in the panelboard stab with which the spring clip is engaged. Thus, the spring clip engages the side of the stab in the conventional manner and the lug is firmly seated against the top surface of the stab through the action of the clamping screw.

Accordingly, a primary object of the instant invention is to provide a novel terminal means for plug-in devices whereby a bolted connection is also obtained.

Another object is to provide a novel combination terminal construction including spring clip means and means for a bolted connection with the latter being utilizable as desired in conjunction with the spring clip means.

These as well as other objects of the instant invention shall become readily apparent after studying the following description of the accompanying drawings in which:

FIGURE 1 is a side elevation of a circuit breaker including the combination terminal means of the instant invention, with the housing cover removed to reveal portions of the circuit breaker operating mechanism. The circuit breaker is shown bolted to a connecting stab of a panelboard. In addition, a fragmentary view of another circuit breaker is shown with the line terminal thereof connected to the same panelboard stab.

FIGURE 2 is a partial cross-section of the circuit breaker of FIGURE l taken through line 2-2 of FIG- URE 1 looking in the direction of the arrows 2 2.

FIGURE 3 is a plan of the circuit breaker of FIG- URE l.

FIGURE 4 is a perspective View of the combination line terminal means.

FIGURE 5 is a side elevation of a panelboard terminal stab adapted to be utilized in cooperation with the terminal means of FIGURE 4.

FIGURE 6 is a cross-section of the stab of FIGURE 5 taken through line 6-6 of FIGURE 5 looking in the direction of the arrows.

FIGURE 7 is an end view of the stab of FIGURE 5 showing a clamping screw mounted thereto.

Now referring to the gures, circuit breaker 10 is of a type described in detail in the Felix E. Myers copending application Serial No. 807,885, now Pat. No. 2,996,589,

3,144,588 Patented Aug. 11, 1964 led April 21, 1959, entitled Pivoted Bimetal, and assigned to the assignee of the instant invention.

Briefly, circuit breaker 10 includes a housing comprised of a base 11 and a mating cover 12 secured to each other by rivet means (not shown). Base 11 and cover 12 cooperate to forma cavity having suitable internal recesses to position and maintain the other elements of circuit breaker 10 in a manner well known to the art.

The current path through circuit breaker 10 comprises load terminal 13, flexible braid conductor 14 to one end of bimetal 15, bifurcated conducting member 16 at the other end of bimetal 15, a pair of iiexible braided conductors 17, contact arm 18, movable contact 19, stationary Contact 20 and line terminal means 25. Bimetal 15 is pivoted near the upper end thereof at pin 21 while the lower end of bimetal 15 carries magnet 22 which cooperates with stationary armature 23 to form a magnetic trip means for circuit breaker 10. The upper surface of magnet 22 forms a latch for releasable cradle 24 which is pivoted to base 11 at embossment 26. A main spring (not shown) interconnects cradle 24 and contact arm 18.

The upper end of contact arm 18 is urged against operating member 27 through the action of the main spring. Member '-27 is pivoted to housing 11, 12 at projections 28 and includes a portion 29 extending through top opening 30 of case 11, 12 to form a manual operating handle for circuit breaker 10.

Line terminal means 25 comprises an inverted U- shaped body portion 31 having inwardly turned arms 32, 33 from which a pair of jaws 34, 35 extend downwardly. A irst lug 36 extends rearwardly and downwardly from body 31. Contact 36 includes a semi-circular notch 3S at the forward end thereof, for a reason to be hereinafter explained, while stationary contact 20 is mounted to lug 37 near the free end thereof. Terminal means 25 also includes lugs 39, 40 which extend upwardly from body portion 31 on opposite sides of lug 36 to cooperate with suitable recesses of housing 11, 12 to maintain terminal means 25 in operative position in a manner well known to the art.

As illustrated in FIGURE l, the right portion of panelboard stab 50 extends through housing opening 48 and is positioned between terminal means jaws 34, 35 with U-shaped spring 49 urging jaws 34, 35 against the side surfaces 52, 53, respectively of stab 50. Forwardly extending lug 36 rests against the top surface 54 of stab 50 being urged thereagainst through the action of clamping screw 6i) whose reduced diameter threaded portion 61 passes through notch 38 to be received by the threaded formation of elongated notch 55 formed in stab 50 and communicating with topsurface 54 thereof. A semicircular depression 65 in the line end of housing 11, 12 cooperates with the elongated enlarged head 64 of clamping screw 60 to act as means for guiding threaded portion 61 through notch 38 into slot 55.

In FIGURE l two combination line terminals 25 are shown engaging the single panelboard stab 50. Circuit breaker 10 is mounted to this position by entering panelboard mounting lug 72 into load side housing depression 71 and thereafter pivoting housing 11, 12 about lug 72 until terminal means lug 36 rests against top surface 54 of stab 50. The other circuit breaker is shown with its line end in juxtaposition to the line end of circuit breaker 10.

In this position the semi-circular depressions 65 cooperate to form a circular guide slot of diameter slightly greater than the diameter of screw head 64. Also in this position notches 3S cooperate to form a circular aperture of a diameter slightly greater than the outside diameter of threaded screw portion 61. It is to be noted that the single clamping screw 60 mechanically secures the line terminals 25 of both circuit breakers 10 and 90.

It is now apparent that end to end breakers can be plugged into a panelboard in the conventional manner, and if additional secureness or contact area is desired, it is merely necessary to insert and tighten screw 60 until the lugs 36 on the connectors 25 are drawn tightly down on the surface 54 of the feeder bus stab 50. In some cases only one ybreaker may be connected to the stab 50 causing an unbalanced condition relative to novel connector 25. However, it has been found that in those cases although the top of screw 60 may lean slightly away from case 11, 12, the length of the threads on screw 60 is sufficient to stabilize screw 60 to provide adequate clamping pressure.

As to the method of forming the threads in the slot 55 of stab 50, several methods may be employed. If the thickness of the stab 50 is substantially greater than the diameter of the screw threaded portion 61, stab 5t) can be drilled and tapped in the usual manner or a self-tapping screw may be used.

However, practical proportions are such that the screw diameter is very close to or larger than the thickness of the stab 50 as shown in FIGURE 7. In this case, stab 50 can be economically notched with staggered teeth that correspond with the cross-section of the screw to be used as shown in FIGURE 5. These teeth are not spiral but are straight and normal to the broad face of the feeder bus as shown in FIGURE 6. In Ithis manner, these teeth can be punched out in a single operation.

Thus, the instant invention provides a novel terminal means having spring clip means for plug-in connections as well as lug means for a bolted type connection. The plug-in means is for convenience of mounting under ordinary conditions while the addition means for the bolted connection secures additional contact area and achieves mechanical stability.

Although we have here described preferred embodiment of our novel invention, many variations and modifications will now be apparent to those skilled in the art, and we therefore prefer to be limited, not by the specific disclosure herein, but only by the appending claims.

We claim:

1. A circuit breaker terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab member through engagement with side surfaces thereof, a body portion integrally joining said jaws at their upper ends; a first lug connected to said body portion and operatively positioned above said jaws to engage a top surface adjacent the side surfaces of a panelboard terminal stab member; said lirst lug extending more in a forwardly direction than said jaws; registry means, including a formation in said first lug, constructed to provide securable engagement between said terminal means and the top surface of a panelboard stab.

2. A circuit breaker terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof, an integral central portion connecting said jaws at their upper lends; a first lug extending from said central portion to engage a top surface of a panelboard terminal stab member; said first lug extending more in a forwardly direction than said jaws; registry means, including a formation in said first lug, constructed to provide securable engagement between said terminal means and the top surface of a panelboard stab; said formation adapted to receive a clamping screw.

3. A circuit breaker terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof, a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first lug operatively positioned above said jaws to engage a top surface of a panelboard terminal stab; said first lug extending more in a forwardly direction than said jaws; registry means, including a formation in said first lug, constructed to provide securable engagement between said terminal means and the top surface of a panelboard stab; said formation adapted to receive a clamping screw; said formation comprising a substantially semi-circular notch extending to the most forward edge of said first lug.

4. A circuit breaker terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof, a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first and a second lug; said first lug operatively positioned above said jaws to engage a top surface of a panelboard terminal stab; said first lug extending more in a forwardly direction than said jaws; registry means, including a formation in said first lug, constructed to provide securable engagement between said terminal means and the top surface of a panelboard stab; said formation adapted to receive a clamping screw; said second lug extending rearwardly and a contact secured to said second lug near the rear end thereof.

5. A circuit breaker terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof, a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first and a second lug; said first lug operatively positioned above said jaws to engage a top surface of a panelboard terminal stab; said first lug extending more in a forwardly direction than said jaws; registry means, including a formation in said first lug, constructed to provide securable engagement between said terminal means and the top surface of a panelboard stab; said formation adapted to receive a clamping screw; said second lug extending rearwardly and a contact secured to said second lug near the rear end thereof; said jaws, said first lug, and said second lug being integral.

6. A circuit breaker including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof, a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion having a first lug operatively positioned above said jaws to engage a top surface of a panelboard terminal stab; registry means, including a formation in said first lug, constructed to provide securable engagement between .said terminal means and the top surface of a panelboard, stab.

7. A circuit breaker including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof, a central portion integral with said jaws at their upper ends for lconnecting said jaws; said central portion including a first lug operatively positioned above said jaws to engage a top surface of a panelboard terminal stab; said first lug extending more in a forwardly direction than said jaws; registry means, including a formation in said first lug, constructed to provide securable engagement between said terminal means and the top surface of a panelboard stab.

8. A circuit breaker 4including a housing, a stationary Contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof; a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first lug operatively positioned above said jaws to engage a top surface of a panelboard terminal stab; said first lug extending more in a forwardly direction than said jaws; registry means, including a formation in said first lug, constructed to provide securable engagement between said terminal means and the top surface of a panelboard stab; said formation adapted to receive a clamping screw.

9. A circuit breaker including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof; a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first lug operatively positioned above said jaws to engage a top surface of a panelboard terminal stab; said first lug extending more in a forwardly direction than said jaws; registry means, including a formation in said first lug, constructed to provide securable engagement between said terminal means and the top surface of a panelboard stab; said formation adapted to receive a clamping screw; said housing having at its said first end a guide formation constructed and operatively positioned to direct a clamping screw through the formation of said first lug.

10. A circuit breaker including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one

of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion having a first and second lug; said first lug operatively positioned above said jaws to engage a top surface of a panelbo-ard terminal stab; said first lug extending more in a forwardly direction than said jaws registry means, including a formation in said first lug, constructed to provide securable engagement between said terminal means and the top surface of a panelboard stab; said formation adapted to receive a clamping screw; said second lug extending from said central portion rearwardly for receiving said stationary contact which is mounted thereto.

ll. A circuit breaker including a housing, a stationary lcontact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws adapted to engage therebetween a panelboard terminal stab through engagement with side surfaces thereof, a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including first and second lugs; said first lug operatively positioned above said jaws to engage a top surface of a panelboard terminal stab; said first lug extending more in a forwardly direction than said jaws registry means, including a formation in said first lug, construct- 6 ed to provide securable engagement between said terminal means and the top -surface of .a panelboard stab; said formation adapted to receive a clamping screw; said second lug being extended rearwardly from said central portion for receiving said stationary contact; said jaws, said first lug, and said second lug being integral.

l2. In combination a panelboard terminal stab and a circuit breaker electrically connected thereto; said circuit breaker including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws biased into engagement with side surfaces of said stab, a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first lug operatively positioned in engagement with a top surface of said stab; said stab including thread receiving means extending to said top surface; a screw extending through a formation of said first lug and received by said thread receiving means for clamping said terminal means to said stab.

13. In combination a panelboard terminal stab and a circuit breaker electrically connected thereto; said circuit breaker including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws biased into engagement with side surfaces of said stab; a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first lug operatively positioned in engagement with a top surface of said stab; said stab including thread receiving means extending to said top surface; a screw extending through a formation of said first lug and received by said thread receiving means for clamping said terminal means to said stab; said housing at its said first end having a guide formation constructed and operatively positioned 1ro direct said screw through the formation of said rst 14. In combination a panelboard terminal stab and a circuit breaker electrically connected thereto; said circuit breaker including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and outof engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws biased into engagement with side surfaces of said stab; a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first lug operatively positioned in engagement with a top surface of said stab; said stab including thread receiving means extending to said top surface; a screw extending through a formation of said first lug and received by said thread receiving means for clamping said terminal means to said stab; said housing at its said first end having a guide formation constructed and operatively positioned to direct said screw through the formation of said first lug; said screw having an elongated head.

15. In combination a panelboard terminal stab and a first and second circuit breaker electrically connected thereto; each of said circuit breakers including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws biased for engagement with side surfaces of said stab; a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first lug operatively positioned for engagement with a top surface of said stab; said stab including thread receiving means extending to said top surface; a screw extending through a formation of said first lug of said first circuit breaker and received by said thread receiving means for clamping said terminal means to said stab; said housing at its said first end having a guide formation; said second circuit breaker having its terminal means jaws in engagement with said stab side surfaces and its terminal means first lug in engagement with said stab top surface; said screw also passing through the first lug formation of said second circuit breaker; the guide formations of said circuit breakers cooperating to form an elongated slot for guiding said screw.

16. In combination a panelboard terminal stab and a first and second circuit breaker electrically connected thereto; each of said circuit breakers including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws biased for engagement with side surfaces of said stab; a central portion integral with said jaws yat their upper ends for connecting said jaws; said central portion including a first lug operatively positioned for engagement with a top surface of said stab; said stab including thread receiving means extending to said top surface; a screw extending through a formation of said first lug of said first circuit breaker and received by said thread receiving means for clamping said terminal means to said stab; said housing at its said first end having a guide formation; said second circuit breaker having its 'terminal means jaws in engagement with said stab side surfaces and its terminal .means first lug in engagement with said stab top surface; said screw also passing through the first lug formation of said second circuit breaker; the guide formations of said circuit breakers cooperating to form an elongated slot for guiding said screw; said screw having an elongated head.

17. In combination a panelboard terminal stab and a first and second circuit breaker electrically connected thereto; each of said circuit breakers including a housing, a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws biased for engagement with side surfaces of said stab; a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first lug operatively positioned for engagement with a top surface of said stab; said stab including thread receiving means extending to said top surface; a screw extending through a formation of said first lug of said first circuit breaker and received by said thread receiving means for clamping said terminal means to said stab; said housing at its said first end having a guide formation; said second circuit breaker having its terminal means jaws in engagement with said stab side surfaces and its terminal means first lug in engagement with said stab top surface; said screw also passing through the first formation of said second circuit breaker; the guide formations of said circuit breakers cooperating to form an elongated slot for guiding said screw; said slot being substantially circular in cross-section.

18. In combination a panelboard terminal stab and a first and Second circuit breaker electrically connected thereto; each of said circuit breakers including a housing,

a stationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a Iterminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a .pair of confronting jaws biased for engagement with side surfaces of said stab; a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion including a first lug operatively positioned for engagement with a top surface of said stab; said stab including thread receiving means extending to said top surface; a screw extending through a formation of said first lug of said first circuit breaker and received by said thread receiving means for clamping said terminal means to said stab; said housing at its said first end having a guide formation; said last recited circuit breaker having `its terminal means jaws in engagement with said stab side surfaces and its terminal means first lug in engagement with said stab top surface; said screw also passing through the first lug formation of said second circuit breaker; the guide formations of said circuit breakers cooperating to form an elongated slot for guiding said screw; said screw having an elongated head; said formations of said first lugs cooperating to define a substantially circular aperture for said screw.

19. In combination a panelboard terminal stab and a circuit breaker electrically connected thereto; said circuit breaker including a housing, a stationary contact disposed Vin said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws biased into engagement with side surfaces of said stab; a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion having a first lug operatively positioned in engagement with a top surface of said stab; said stab including thread receiving means extending to said top surface; a screw extending through a formation of said first lug and received by said thread receiving means for clamping said terminal means to said stab; the thread receiving means of said stab comprising an elongated slot notched with staggered teeth.

20. In combination a panelboard terminal stab and a circuit breaker electrically connected thereto; said circuit breaker including a housing, a rstationary contact disposed in said housing, a movable contact disposed in said housing and operable into and out of engagement with said stationary contact and a terminal means secured to said housing at a first end thereof; one of said contacts being electrically connected to said terminal means; said terminal means comprising a pair of confronting jaws biased into engagement with side surfaces of said stab; a central portion integral with said jaws at their upper ends for connecting said jaws; said central portion having a first lug operatively positioned in engagement with a top surface of said stab; said stab including thread receiving means extending to said top surface; a screw extending through a formation of said first lug and received by said thread receiving means for clamping said terminal means to said stab; the thread receiving means of said stab comprising an elongated slot notched with staggered teeth; said teeth being normal to the faces of said stab.

References Cited in the file of this patent UNITED STATES PATENTS 2,105,396 Bakke Jan. 11, 1938 2,719,203 Gelzheiser Sept. 27, 1955 2,735,043 Speck Feb. 14, 1956 2,910,629 Casey Oct. 27, 1959 

1. A CIRCUIT BREAKER TERMINAL MEANS COMPRISING A PAIR OF CONFRONTING JAWS ADAPTED TO ENGAGE THEREBETWEEN A PANELBOARD TERMINAL STAB MEMBER THROUGH ENGAGEMENT WITH SIDE SURFACES THEREOF, A BODY PORTION INTEGRALLY JOINING SAID JAWS AT THEIR UPPER ENDS; A FIRST LUG CONNECTED TO SAID BODY PORTION AND OPERATIVELY POSITIONED ABOVE SAID JAWS TO ENGAGE A TOP SURFACE ADJACENT THE SIDE SURFACES OF A PANELBOARD TERMINAL STAB MEMBER; SAID FIRST LUG EXTENDING MORE IN A FORWARDLY DIRECTION THAN SAID JAWS; REGISTRY MEANS, INCLUDING A FORMATION IN SAID FIRST LUG, CONSTRUCTED TO PROVIDE SECURABLE ENGAGEMENT BETWEEN SAID TERMINAL MEANS AND THE TOP SURFACE OF A PANELBOARD STAB. 